On one substrate a Diesel Oxidation Catalyst (DOC) and a Lean NOx Trap (LNT) are combined. This component has the high HC and CO removal efficiency of a fully formulated DOC, with the ability of a LNT to trap and reduce NOx.
The exhaust from the engine flows through the LNT.2 catalyst. This catalyst oxidizes HC and CO efficiently. In addition the catalyst traps NOx under lean engine operation conditions. Trapped NOx is released from the catalyst when the engine operation mode is switched to rich conditions. During rich regeneration, the NOx is converted into N2, and NH3 (ammonia) is generated over the LNT.2.